When most people think about email marketing, they picture one-off emails sent to targeted portions of their database. While those emails are certainly a very important part of a healthy marketing strategy, there's another type of email that can be a powerful addition to your mix: transactional emails.

We know you love a good inspirational roundup, so we dug through our inboxes to find some standout examples of transactional emails. Not only have we collected these emails, but we've also dissected them to figure out what makes them truly great. For your browsing pleasure, we've taken the liberty of dividing these emails into three categories: confirmation emails, welcome emails, and a handful of miscellaneous ones. Read on to check them all out, or click the previous links to jump to your desired section.

Note: If you're a HubSpot customer and would like to use transactional emails, you can now request the transactional email add-on. Learn more about it here.

15 Examples of Awesome Transactional Email Campaigns

Confirmation Emails

To start us off, here's a lengthy transactional email from our friends at Airbnb. It's chock-full of highly personalized and useful information, including a map of the surrounding area, directions to the apartment from the airport, house rules, and some general logistics around cancellation and payments.

One thing you'll notice many of these examples have in common is an abundance of relevant deep links. These links take you to specific pages on a website rather than forcing you to navigate there yourself. All of the links in this email are deep links, making it easy for customers to dive right back into the Airbnb website and re-engage.

The email also strategically places the "Invite Friends" CTA at the top, catching happy customers right after they've made a reservation and a relationship has been established. They take this one step further by including social media buttons at the bottom. These tactics can help them slowly build a community of brand evangelists.

The subject line of this transactional email is classic Amazon -- straightforward, specific, with no frills. In the body, they include just enough deep links about the order and your account to be useful, but they're relatively unobtrusive if you don't want to look at them.

They also are smart about how they link to the shipment tracking. Most other retailers simply include a link to track the package on the shipping company's website, but Amazon knows better. They link the "Track Your Package" button to their own tracker, taking advantage of the biggest and best CTA in this email to re-engage customers on their website. Why's that important? When customers go back to the website, Amazon can continue to collect data and show advertising. Then, that data is used to fuel their eerily accurate product recommendations -- some examples of which are showcased at the bottom of this email. Brilliant.

On the opposite end of the spectrum is this flight confirmation email from Southwest. On first glance, the amount of content in here feels a little overwhelming, but there are some good lessons to take away from the email.

An interesting tactic they use is placing the relevant links in the "navigation" at the top and at the bottom before the footer. Once those small details are taken care of, the body of the email can use a mix of transaction-related and promotional content. When we marked off which portions of the email are transaction-related (pink) and which ones are promotional (blue), it actually turned out to be a surprising 50/50. They manage to direct the eyes to the promotional content by making it much more colorful and loading it with images, almost like an optical illusion. While we might not recommend including so much content in your emails, knowing that you can blend transactional and promotional content is important.

The one thing to consider when blending the two types of email is that the definition of "transactional email" varies by country due to differences in legislation -- what some countries consider "transactional" could be considered "promotional" in another. For example, many North American marketers are probably well acquainted with American CAN-SPAM laws and their Canadian counterpart, CASL. By American standards, this email could be considered transactional because its main purpose is to continue a transaction I initiated with Southwest. By Canadian standards, however, this email could fail the transactional standards, and all the sections highlighted in blue might need to be removed.

The next couple examples are similar in that they are designed to be read on mobile devices. Why? The transactions are typically made while someone's on the go -- purchasing food, riding in the car, etc. -- so it makes sense that their associated emails are designed to be mobile-first.

This receipt is sent by Union Square Donuts via Square (the company that processes their payments). The photo at the top makes me immediately crave more donuts despite just scarfing down way too many. The feedback request right below is inviting and friendly (when you click on either of the faces, it brings you to a webpage where you can provide a more detailed response). The email ends with a few options to continue your experience with the brand online, with a button leading to a Square-hosted online store and links to engage with the merchant on social media.

Below is a receipt for a payment made through Venmo's mobile app. Everything about this email is efficient and scannable -- perfect for mobile viewing. The subject line is direct and personalized to the specific transaction, and the inclusion of the friend's picture in the body of the email humanizes the transaction.

But Venmo is not just a peer-to-peer payment app -- it's also a social platform. To grow its network and encourage you to engage with people on the platform, Venmo includes CTAs to "like," "comment," and "invite friends!" in the body of the email.

It's impossible to talk about mobile transactions without talking about ride-sharing apps. Lyft's post-ride email does a great job of promoting relevant features and information. For example, split payments were introduced in December of 2014, but for those of us who are constantly inundated with information and promotions from lots of companies, the announcement could have gone easily unnoticed. This email is the perfect place to promote the feature while its usefulness is still top-of-mind.

I also love the inclusion of the helpful deep links for "Lose something?" and "Add tip," which probably go a long way to head off two of their most frequently asked questions. They also include links to the help center, careers, page, and blog in the footer, which are welcome options to engage curious users with further reading.

This is another example of a payments processor, LevelUp, sending a receipt on behalf of a merchant, Life Alive. However, unlike Square and Union Square Donuts in the example above, LevelUp is the focus here. This makes sense because structurally, LevelUp relies on the customer (not the merchant) for product adoption, so it's important that customers love and understand how LevelUp works.

LevelUp does an excellent job of going after those goals in this email, promoting gift cards and spending rewards, and clearly laying out the mechanics of the transaction. The progress bar is also a brilliant visualization for motivating customers to spend more. I also love how easy they make getting in touch -- you just have to reply to the email. If only it were always that easy.

Welcome Emails

For our first welcome email, we turn an eye to Trello, which is known for its fun brand and the most adorable mascot ever. Here, they cleverly take advantage of an oft-overlooked component of email: the "from" name and email address. For new users who are likely unfamiliar with the company's personality, this detail gives them a sense of it immediately.

The body of the email contains a few different options to help users get started, with more of those great deep links to a tour and a video introduction. They also understand the value of getting users on the mobile app, kick-starting the habit-forming loop of usage.

Zapier takes a refreshing, low-tech approach to the welcome email. This is crafted to look like a personal note sent directly to the user from the CEO. Instead of overwhelming a new user by throwing all the available resources at them, they boil this down to one clear CTA: Check out their use cases. For more curious users, Zapier includes a link in the postscript to help documentation, and make it super easy to get help by allowing people to simply respond to the email with questions.

This welcome email from digit upends any pre-conceived notions a user might have about the finance industry. It's sent from a real person and the copy is written with lots of personality. In their attempt to disrupt an industry dominated by giants, digit starts with something as simple as the welcome email. They take this chance to establish a relationship, build trust, and strengthen their brand. Not bad for just 70 words.

The one thing I wish they would include is some sort of concrete CTA to help onboard users further or provide further reading. But they have an interesting business proposition and I am curious to learn more after this.

Instacart has a clear agenda in this welcome email. First, they want to get people shopping, and second, they want to get people using their mobile apps -- these two CTAs are repeated and rephrased through the body of the email. Sandwiched in between these CTAs is information about their customer service, an equally important component. They also sneak in a referral ask at the end, including an incentive for the referrer to receive Instacart credit.

Heroku takes the route of simplicity and clarity when welcoming their new users. They include only one link in the body of the email in the "Get Started Now" button, creating a clear conversion path for recipients. They also include some offbeat links in the footer of the email -- in addition to the standard links to Twitter and Facebook, there are also links to their blog, Flickr, and Vimeo for an inside look into the company and its culture.

Miscellaneous

This email from Discover is an awesome snapshot of my spending. They start things off with a brief explanation of what the email will contain. Then, they do a great job of highlighting the rewards I earned, which makes me want to go out and use the credit card to get more cash back. I also feel like part of an exclusive group, being invited to give feedback on the email and improving the experience for my fellow customers and me. Then, the buttons at the bottom to download mobile apps and engage with the company on social media serve to illustrate that Discover is a credit card company for Millennials.

We all know how easy it is fill an email with too much information and content, so it's really admirable is when someone is able to get their point across in a succinct way. In their confirmation email below, Dropbox abides by that principle. The sparse copy includes only the bare minimum of relevant links, and they use the room left over to promote relevant content. I can scan and understand this email quickly without worrying that I could have missed something important.

TeuxDeux's product is simple, easy-to-use, and run by a small team -- and their emails mirror those sentiments. This password reset email below showcases their signature friendly copy (including an awesome pun) and is sent from a real person with a real email address. Most password reset emails come across as incredibly robotic, so this friendly, funny password reset email is one that'd stand out in a crowded inbox.

These are just some of our favorite transactional emails we've encountered. Who sends you transactional emails that you love? Share your favorites in the comments.